Copy a DATASET to XMLDOCUMENT

How can I copy my dataset data type to an XMLDOCUMENT data type?

do u need something like this.

Dim xmlFile As String = "file.xsd"
Dim myStreamWriter As New System.IO.StreamWriter(xmlFile)
ds.WriteXmlSchema(myStreamWriter)

myStreamWriter.Close()

no that creates a file... i need the xml to be in an xmldocument....

maybe if i did a query to the sql server and got the dataset back in xmldocument data type... dont know how to that...